/**
 * Copyright 2017 Pivotal Software, Inc.
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * https://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.micrometer.spring.web.client;

import io.micrometer.core.instrument.Tag;
import io.micrometer.core.lang.Nullable;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.web.client.RestTemplate;

/**
 * Provides {@link Tag Tags} for an exchange performed by a {@link RestTemplate}.
 *
 * @author Jon Schneider
 * @author Andy Wilkinson
 */
@FunctionalInterface
public interface RestTemplateExchangeTagsProvider {

    /**
     * Provides the tags to be associated with metrics that are recorded for the given
     * {@code request} and {@code response} exchange.
     *
     * @param urlTemplate the source URl template, if available
     * @param request     the request
     * @param response    the response (may be {@code null} if the exchange failed)
     * @return the tags
     */
    Iterable<Tag> getTags(@Nullable String urlTemplate, HttpRequest request,
                          @Nullable ClientHttpResponse response);

}
